1. Field of Invention
The present invention relates to the preparation of assay substrates, and, more specifically, to the application of a blocking material to an assay substrate that has been printed with features.
2. Description of Related Art
An assay substrate is a surface upon which various chemical and/or biological analyses can be performed. Examples include microarray plates, glass slides, and microtiter plates. A microtiter plate is a flat plate that has multiple “wells” formed in its surface. Each well can be used as a small test tube into which various materials can be placed for the purposes of performing chemical analysis. One illustrative use of microtiter plates includes an enzyme-linked immunosorbent assay (ELISA), which is a modern medical diagnostic testing technique.
In ELISA, in general, a capture antibody is printed in the bottom of a well in a microtiter plate. The capture antibody has specificity for a particular antigen for which the assay is being performed. A sample to be analyzed is added to the well containing the capture antibody, and the capture antibody “captures” or immobilizes the antigen contained in the sample. A detect antibody is then added to the well, which also binds and/or forms a complex with the antigen. Further materials are then added to the well which cause a detectable signal to be produced by the detect antibody. For example, when light of a specific wavelength is shone upon the well, the antigen/antibody complexes will fluoresce. The amount of antigen in the sample can be inferred based on the magnitude of the fluorescence. In another example, a compound can be added to the well that causes the detect antibody to emit light within a predetermined wavelength (e.g., 400-500 nm). This light can be read by a CCD camera to measure the optical brightness of the emitted light.